Bovine papillomavirus (BPV) is an oncogenic virus related to serious livestock diseases. Oncoproteins encoded by BPV are involved in several steps of cellular transformation and have been reported as presenting clastogenic effects in peripheral lymphocytes and primary culture cells. The aim of this study was to evaluate the clastogenic potential of BPV types 1, 2, and 4 by comet assay. Peripheral blood was collected from 37 bovines, 32 infected with different levels of papillomatosis (12 animals have no affection) and five calves, virus free (negative control). The viral identification showed presence of more than one virus type in 59.375% of the infected animals. Comet assay was performed according to alkaline technique. The Kruskal-Wallis test showed statistical difference between the negative control group and infected animals (P = 0.0015). The Dunn post hoc test showed difference comparing the infected animals with calves. Mann-Whitney U test verified no difference between animals infected with only one viral type and animals presenting more than one viral type. The comet assay is considered an efficient tool for assessment of damage in the host chromatin due to viral action, specifically highlighting viral activity in blood cells.

ABSTRACT. Bovine papillomaviruses (BPV) are the causal agents of benign and malignant lesions; they can cause dramatic economic losses in cattle. Although 10 virus types have been described, three types are most common in tumors, namely BPV-1, -2 and -4. Previous studies have reported BPV in blood cells and the possibility of blood acting as a latent virus site and/or transmission agent of virus dissemination. We studied a Holstein dairy herd in Pernambuco, Brazil, in which several animals showed severe cutaneous papillomatosis, without previous determination of BPV types. Blood samples and short-term lymphocyte cultures were collected from 54 cows. We compared the BPV types detected in peripheral blood to those identified in the respective lymphocyte cultures: BPV-1 was detected in 74% and BPV-2 in 87% of the whole blood samples. Simultaneous virus presence (BPV-1 and BPV-2) was found in 65% of the blood samples. BPV-1 or BPV-2 were detected in the lymphocyte cultures in 93% of the samples, and both in 89%. The detection of viral DNA in whole blood and in lymphocyte cultures is evidence that this virus is carried by lymphocytes.

The bovine papillomavirus (BPV) is the etiological agent of bovine papillomatosis, which causes significant economic losses to livestock, characterized by the presence of papillomas that regress spontaneously or persist and progress to malignancy. Currently, there are 13 types of BPVs described in the literature as well as 32 putative new types. This study aimed to isolate viral particles of BPV from skin papillomas, using a novel viral isolation method. The virus types were previously identified with new primers designed. 77 cutaneous papilloma samples of 27 animals, Simmental breed, were surgically removed. The DNA was extracted and subjected to PCR using Delta-Epsilon and Xi primers. The bands were purified and sequenced. The sequences were analyzed using software and compared to the GenBank database, by BLAST tool. The viral typing showed a prevalence of BPV-2 in 81.81% of samples. It was also detected the presence of the putative new virus type BR/UEL2 in one sample. Virus isolation was performed by ultracentrifugation in a single density of cesium chloride. The method of virus isolation is less laborious than those previously described, allowing the isolation of complete virus particles of BPV-2.

ABSTRACT. Bovine papillomavirus (BPV) is an oncogenic virus associated with benign and malignant lesions, which result in notable economic losses. Peripheral blood samples and cutaneous papillomas were obtained from four adult beef cattle. Viral molecular identification was performed using specific primers for BPV-1, -2 and -4 in blood diagnosis and FAP59/FAP64 for skin papillomas. Histopathologic examination was done as a complementary and differential diagnosis. The fragments were purified, sequenced, and compared using BLASTn. The blood diagnosis showed the presence of BPV-2 and the analysis of cutaneous papillomas showed the presence of BPV-4, a new First description of BPV-12 and putative type BAPV8 in Brazil putative virus type BAPV8, and BPV-12, revealing for the first time the presence of BPV-12 and the putative type BAPV8 in beef cattle in Brazil. The sequences were deposited in the GenBank. Histopathology revealed acanthosis, hyperkeratosis, and koilocytosis in all samples analyzed. The presence of BAPV8 and BPV-12 in Brazil emphasizes the ubiquitous dissemination of BPVs in the herds of Brazil.